Open Mobile Alliance Device Management Version 1.2 (OMA DM V1.2) is a unified DM specification specified by the OMA DM Working Group for DM. A DM system provides a low cost solution that may be used by a third party to manage and set an environment and configuration information of wireless network terminal devices (such as mobile phone terminals and functional objects in terminals), solve problems occurring during the use of the network devices, install and update software and firmware in an over the air (OTA) manner, and provide more humanized and personalized services, so as to improve the user experience. The third party may be a mobile operator, a service provider, or an information management department of a partner.
FIG. 1 is an architecture diagram of a conventional OMA DM system. A DM agent in a terminal device may be configured to interpret and execute a management command sent by a DM server. A management tree stored in the terminal device may be regarded as an interface, through which the DM Server manages the terminal device according to a DM protocol. The management tree may include some basic Management Objects (MOs). The DM server achieves the objective of controlling the terminal MOs by operating management tree objects. Operation commands may include Get, Replace, Exec, Copy, and Delete.
An MO typically has its own identifier, which is referred to as a Management Object Identifier (MOI) and is used to uniquely identify the MO.
For the DM management tree, the MOs consist of nodes, such as a root node, internal nodes, and leaf nodes. The root node is the topmost node in the management tree. The leaf node may have a node value, but cannot have any child node. The internal node cannot contain a node value, but may have child nodes. However, a topmost node of an MO or in a management sub-tree may also be referred to as a root node of the MO or the management sub-tree. Addressing of nodes is performed through Uniform Resource Identifiers (URIs). The URIs are categorized into absolute URIs and relative URIs. Typically, the absolute URI is a URI starting from the root node, for example “./A/B/C/D”, and the relative URI is a URI using some position as a reference, for example “A/B/C/D”.
In the management tree, unnamed nodes may exist. These unnamed nodes act as placeholders and are only named when being instantiated by a server or a user terminal. Nodes of this type are referred to as “x” nodes. After being named, the node and sub-nodes under the node are referred to as instances. If the node is the root node of an MO, the node and the sub-nodes under the node are referred to as MO instances.
The OMA DM defines a Device Management Account (DMAcc) standard MO, which stores the relevant parameters required when a user terminal and a server establishes a connection, such as connection reference, a server address, and authentication information.
The OMA DM also defines an Inbox standard MO. By using the object, when a server adds an MO to a user terminal, an absolute path for the adding may not be provided, and the user terminal is informed of an MOI, so that the user terminal resolves a path of the object.
The premise of managing a user terminal by the DM server is that the DM server needs to know relevant information of a management tree in the current user terminal, such as positions, names, and node values of nodes. Sometimes, the user terminal does not inform the server of the information, and the information of multiple terminals may be different.
Conventionally, an MO instance is located by using a relative URI and adding MOI information to a management command. The problem with this technique is that it is based on the premise that relative URIs in multiple terminals are consistent. However, if the relative URIs in the terminals are inconsistent, this technique cannot be applied.